Faculty

Yoshiaki Azuma
Ph.D., Kyushu University School of Medicine, Japan, 1997
Assistant Professor
3037 Haworth Hall; (785)-864-7540, e-mail:

Posttranslational protein modification modulates the biochemical and cell biological function of the proteins and has essential role to regulate various physiological phenomena. SUMO family of protein is small ubiquitin-related protein that modifies various cellular proteins to be conjugated to substrates in a manner similar to Ubiquitin (SUMO modification). Genetic analysis indicates that SUMO modification is essential for viability in eukaryote. Defect in SUMO modification caused aberrant mitosis in yeast and fruit fly, suggesting the SUMO modification pathway is involved in proper progression of mitosis. I have found that mitotic specific SUMO modification has crucial role in chromosome segregation by using Xenopus egg extracts in vitro cell cycle assay system. My lab will focus on understanding a role of mitotic SUMO modification in respect to chromosome segregation, especially, the function of SUMO modification on DNA topoisomerase II (TopoII), which is a major SUMO modified substrate in mitosis. During mitosis, chromosomes dramatically change their structure to organize proper structure for mitotic chromosome. This event is essential to separate sister chromosomes faithfully in anaphase of mitosis. TopoII is one of the key enzymes to organize proper chromosome structure, thus SUMO modification of TopoII suggested to have important role of regulation of chromosomal structure during mitosis. My lab will utilize Xenopus egg extracts in vitro cell cycle assay to study biochemical and cell biological function of mitotic SUMO modification.
In addition, I have identified specific enzyme that is essential for mitotic SUMO modification in Xenopus egg extracts. My lab will study the regulatory mechanism of this enzyme how this enzyme mediate mitotic specific modification.

Representative Publications

• Azuma, Y., Arnaoutov, A., Anan, T. and Dasso, M. PIASy is essential for SUMO-2 modification of DNA topoisomerase II in Xenopus mitotic extract. (2005) EMBO J. Jun 15;24(12):2172-82.
• Arnaoutov, A., Azuma, Y., Ribbeck, K., Joseph, J., Boyarchuk, Y. and Dasso, M. (2005) Crm1 is a Mitotic Effector of Ran-GTP in Somatic Cells. Nat Cell Biol. Jun;7(6):626-32.
• Azuma, Y., Arnaoutov, A. and Dasso, M. (2003) SUMO-2/3 Regulates Topoisomerase-II in Mitosis. J Cell Biol. Nov. 10;163(3):477–487
• Azuma, Y. and Dasso, M. (2002) A new clue at the nuclear pore: RanBP2 is an E3 enzyme for SUMO1. Dev Cell. Feb. 2 (2):130-1.
• Azuma, Y., Tan, SH., Cavenagh, MM., Ainsztein, AM., Saitoh, H. and Dasso, M. (2001) Expression and regulation of the mammalian SUMO-1 E1 enzyme. FASEB J. Aug 15 (10):1825-27.
• Azuma, Y, Renault, L, Garcia-Ranea, JA, Valencia, A, Nishimoto, T and Wittinghofer, A. (1999) Model of the Ran-RCC1 Interaction using Biochemical and Docking Experiments. J Mol Biol. Jun 18;289 (4):1119-1130.
• Azuma, Y., Hachiya, T., and Nishimoto, T. (1997) Inhibition by anti-RCC1 monoclonalantibodies of RCC1-stimulated guanine nucleotide exchange on Ran GTPase. J Biochem (Tokyo) Dec;122 (6):1133-8.
• Azuma, Y., Seino, H., Seki, T., Uzawa, S., Klabe, C., Ohba, T., Wittinghofer, A., Hayashi, N. and Nishimoto, T. (1996) Conserved histidine residues of RCC1 are essential for nucleotide exchange on Ran. J Biochem 120 ; 82-91